1. Field
Embodiments disclosed herein generally relate to a magnetic read head for use in a hard disk drive.
2. Description of the Related Art
The heart of a computer is a magnetic disk drive which typically includes a rotating magnetic disk, a slider that has read and write heads, a suspension arm above the rotating disk and an actuator arm that swings the suspension arm to place the read and/or write heads over selected tracks on the rotating disk. The suspension arm biases the slider towards the surface of the disk when the disk is not rotating but, when the disk rotates, air is swirled by the rotating disk adjacent a media facing surface (MFS), such as an air bearing surface (ABS) of the slider, causing the slider to ride on an air bearing a slight distance from the surface of the rotating disk. When the slider rides on the air bearing, the write and read heads are employed for writing magnetic impressions to and reading magnetic signal fields from the rotating disk. The read and write heads are connected to processing circuitry that operates according to a computer program to implement the writing and reading functions.
One type of conventional sensor used in the read head is a scissor sensor. The scissor sensor stack typically has two free magnetic layers with magnetizations that move in a scissor fashion relative to each other. The scissor sensor stack has a first surface located at the MFS and a second surface opposite the first surface and a bias material is typically disposed adjacent the second surface of the sensor stack. Side shields, such as synthetic antiferromagnetic (SAF) structures, typically laterally bookend the sensor stack and the bias material. The side shields minimize the demagnetization energy of the dual free layer. However, in this configuration, strong interaction between the SAF structures and the bias material can occur, such that the stray field from the SAF structures disturbs bias material stabilization.
Therefore, an improved read head is needed.